Senior Software Engineer - Backend

We’re On the Beach! Since 2003, we've been rewriting the rules of how people discover, book, and experience their perfect getaway. What started as connecting people to short-haul beach holidays has evolved into something much bigger - premium beach destinations, long-haul adventures, and vibrant city breaks – and that’s just the beginning of our story.

We send around two million holidaymakers on their dream breaks every year. And we're still growing.

Powered by our deep-rooted entrepreneurial spirit, proprietary tech, curiosity and our incredible people, we’re accelerating - delivering best in class technology, the ultimate holiday app, and experiences that keep our customers coming back for more.

Ready to build the future of travel with us?

About the Role As a Senior Software Engineer (Backend), you’ll design and build scalable applications, services and platforms across On the Beach.

This is a full-stack engineering position with a stronger emphasis on backend engineering, distributed systems and cloud-native architecture.

Our backend engineers solve a wide variety of problems. You could be working on systems responsible for communicating with external travel suppliers, processing large volumes of hotel inventory and pricing information, powering customer search experiences, or ensuring bookings move reliably through complex transactional workflows.

You’ll work across the development lifecycle and collaborate with engineers, product managers and other technical specialists to design, build, deploy and operate reliable software t you’ll be doing day to day Designing and building scalable backend applications and services

Developing APIs used by customer-facing applications and internal systems

Integrating with external suppliers and third-party platforms

Building systems that process high volumes of requests and data Designing distributed and event-driven architectures

Working with asynchronous messaging and streaming technologies

Solving problems around performance, latency, resilience and availability

Improving caching and data-access strategies

Building reliable transactional workflows

Developing applications and services within AWS Deploying and operating containerised applications

Improving monitoring, alerting and observability

Exploring AI-assisted engineering and modern development tooling

At Senior level, you’ll be expected to understand the wider system rather than only the individual service you are working on.

You should be comfortable considering how systems behave in production, identifying failure scenarios and balancing scalability, resilience, maintainability and delivery speed.

We’re looking for strong full-stack engineers whose experience leans towards backend and platform engineering.

You’ll be a great addition to our team if you have the following skills, knowledge and experience

Strong commercial backend software engineeringC# and .NET or comparable experience building modern backend applications

Designing and developing APIsBuilding distributed systems and service-oriented architectures

Developing cloud-native applications, ideally within AWS Working with messaging, asynchronous processing or event-driven architecture

Designing reliable integrations with external or internal systems SQL and/or No

SQL data stores

Building scalable systems handling significant traffic or data volumes

Performance optimisation, caching and latency reduction

Designing for resilience and failure

Containerisation and orchestration technologies such as Docker and Kubernetes Observability, monitoring and operating production systems

Automated testing and modern engineering practices

We don’t expect candidates to have worked with every technology in our stack. Strong engineering fundamentals and evidence of solving comparable problems at scale are more important than matching every individual tool.

What we’re looking for at Senior level

Beyond the technologies themselves, we’re looking for someone who:

Can independently solve complex engineering problems

Thinks about the customer and commercial impact of technical decisions

Understands the trade-offs between speed, quality and long-term maintainability

Can contribute meaningfully…